The present invention relates in general to oil water separators which periodically require cleaning.
Oil-water separators are presently installed in marine vessels, such as ships of the U.S. Navy, for treatment of oily wastewater. Oil removed by such treatment is retained on board within a waste oil tank while the cleansed water is discharged overboard through a drain line from the separator tank. Treatment of the oily wastewater currently involves its gravitational flow through parallel stacked plates of a plastic type material within the separator tank, onto which oil sludges are thereby deposited. Such stacked plates therefore require periodic cleansing for removal of the sludges in order to maintain separator functioning at its optimal level. In view of the laborious nature of current cleansing procedures utilized, disposal of hazardous waste is costly. It is therefore an important object of the present invention to provide for less costly and more efficient in-situ cleansing of the foregoing type of oil-water separators.
In accordance with the present invention, enhanced in-situ cleansing of contaminated stacked plates of an oil-water separator is performed by injection of a commercially available chemical agent into the tank chamber of the separator, with the cleaning action of the chemical agent enhanced by an air sparging array operationally positioned in underlying relation to the plate stacks. Operation of the air sparging array is arranged to achieve optimized dispersion of the chemical cleaning agent during gravitationally induced downflow for more effective sloughing of the oily sludge accumulated on the stacked plates as a result of the oil separation treatment performed. The air sparging array is accordingly configured to provide for emergence therefrom, at appropriately spaced locations underlying the plate stacks, air bubbles of varying size for most efficiently imparting turbulence to the chemical cleansing agent and/or inject oxygen from the air where the cleansing agent includes an active aerobic microbe. Such air bubbles are derived from pressurized air supplied to the array from a ship service source.